AAK. For your 1774 Vs 1758 chapter.
But the H1/2/5 can open a bit wider at the longest tele, F/3.7 vs. F/4.5 - so in the end who has more light?
I guess it is somewhat hard to quantify. I thought that F stops were the final word on which camera lets in more light, but there seem to be effects other than how much the lens can open....